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Finding the Fourth Proportional to 2.13, 3.20 and 0.80

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Solution

The fourth proportional to 2.13, 3.20 and 0.80 is: 1.20

Step by Step Solution

  1. Step 1: Write the proportion equation
    2.13 : 3.20 = 0.80 : x
  2. Step 2: Convert to fraction form
    2.13/3.20 = 0.80/x
  3. Step 3: Cross multiply
    2.13x = 3.20 × 0.80
  4. Step 4: Simplify right side
    2.13x = 2.55
  5. Step 5: Solve for x
    x = 2.55/2.13
  6. Step 6: Final answer
    x = 1.20

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.